I hope your random shin pains settle down & it’s not a permanent thing & if it is you find a way to soothe it.
Having a child with sensory issues certainly requires a lot more patience & understanding. I think not worrying what others think & doing what’s best for you & your son is most important. My son loves riding on my lap too. Have you thought of getting some kind of mobility scooter for days you are exhausted or in pain? There are so may bits of equipment that can make your life easier. Have you chosen a school for your son? Is her excited about going to school? It does free your days up & its wonderful to see my son growing & learning so much but you aren’t left with much time during the week to just be with them.